Unravelling the behavior of nanostructures during digestion and absorption

The food industry is increasingly focused on preventing nutrition-related diseases and improving consumers’ wellbeing. As a result, there is a growing trend towards healthy foods, enriched with bioactive compounds (such as vitamins, probiotics, bioactive peptides and antioxidants) produced through the application of innovative and safe technologies. In this context, the development of novel delivery systems for food applications through the use of nanotechnology has been extensively explored [1]. In fact, the encapsulation of bioactive compounds in bio-based nanostructures have been reported as promising mean of protecting the valuable bioactive compounds and providing new functionalities (e.g. increase of bioavailability). However, the use of very small particle sizes may alter the biological fate of the ingested materials and bioactive compounds, which could potentially have adverse effects on human health [2]. Therefore, the emerging field of nanotechnology offers new challenges to food industry not only by offering novel tools to improve food quality and human health, but also by introducing questions about nanostructures’ behaviour within the human body. The challenges that must be overcome before nanotechnology can be entirely embraced by food industry, includes the optimisation of nanostructures’ formulations to increase stability and bioactive compounds’ bio availability and the risk assessment of their use in food. The understanding of the behaviour of different nano-based delivery systems (e.g. nanoemulsions, nanoparticles) under digestion conditions, assessing their efficiency and safety is therefore of utmost importance to enable its widespread application in the food industry. This evaluation can be challenging, however, there are opportunities to take advantage from the lessons learned from pharmaceutical industry and of the considerable progress in the development of more realistic in vitro models to more accurately predict the behaviour of bio-based nanostructures once ingestedinfo:eu-repo/semantics/publishedVersio

Lipid-based nanostructures as strategies to enhance curcumins bioavailability: effect of carrier oil physical state

This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the Project PTDC/AGR-TEC/5215/2014, the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Incorporation of solid lipid nanoparticles into stirred yogurt: effects in physicochemical and rheological properties during shelf-life

The aim of this work was to develop a yogurt fortified with curcumin. Curcumin is a lipophilic compound with a wide range of biological activities; however, it presents low water solubility and low bioavailability, and therefore it was the first to be encapsulated in solid lipid nanoparticles (SLNs). Then the influence of the incorporation of curcumin-loaded SLNs on the physicochemical (i.e., pH, titratable acidity, syneresis and color) and rheological properties of yogurt during its shelf-life (30 days at 4 °C) was evaluated. SLN incorporation into yogurt did not affect pH and titratable acidity compared to the control (i.e., plain yogurt) during shelf-life, even though the yogurt with SLNs presented lower values of pH (4.25 and 4.34) and acidity (0.74% lactic acid and 0.84% lactic acid) than the control in the end, respectively. Furthermore, the yogurt with SLNs presented slightly higher values of syneresis than the control during the shelf-life; however, it did not present visual differences in whey separation. Relative to the color, the incorporation of SLNs into the yogurt imparted a strong yellow color to the sample but did not affect color stability during shelf-life. Both samples showed flow curves with yield stress and shear-thinning behavior during shelf-life, and, regarding the viscoelastic behavior, both showed a typical weak viscoelastic gel with an elastic structure. Overall, curcumin-loaded SLNs incorporation did not affect the physicochemical and rheological stability of yogurt during shelf-life, showing a promising application for the development of new functional foods.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and by LABBELS Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020.info:eu-repo/semantics/publishedVersio

Effect of bio-based nanostructures in curcumin bioaccessibility: physical state and carrier oil type

Curcumin (CUR), a natural phytochemical from Curcuma longa, presents a wide range of biological activities such as antioxidant, antimicrobial and antitumoral effects. However, it exhibits very low water solubility and low bioavailability, which limit its food application. To overcome these limitations, nano-scale delivery systems (e.g. nanoemulsions (NE) and solid lipids nanoparticles (SLN)) can be developed to improve its bioavailability and stability. Also, it is essential to assess nanoformulations behaviour and CUR fate in the gastrointestinal (GI) tract. This work aimed at understanding the effect of nanoformulations physical state (NE and SLN) and oil type used in NE (medium chain triglycerides (MCT) and long chain triglycerides (LCT)) on CUR stability, bioaccessibility and effective bioavailability when submitted to an in vitro digestion process. Nanoformulations stability was characterized at each stage of digestion. At the end of digestion, free fatty acids (FFA) release, CUR stability, bioaccessibility and effective bioavailability were determined. Cellular uptake was evaluated using Caco-2 cells. All nanoformulations showed to be stable until gastric phase, from which an increase of particle size was observed. However, SLN showed to be more stable than NE. Regarding FFA release, both NE released higher FFA amount than SLN. Also, NE-MCT released a higher FFA amount than NE-LCT. Although SLN and NE-LCT promoted similar CUR stability, SLN presented the lowest CUR bioaccessibility and effective bioavailability. NE-MCT exhibited lower CUR bioaccessibility but promoted a higher CUR stability and effective bioavailability when compared to NE-LCT. Thus, it was possible to observe that the physical state and oil chain length have a high effect in nanoformulations digestibility and on CUR fate in the GI tract. This work contributed to the progress of the knowledge on the development of different bio-based nanoformulations with improved CUR bioavailability, by collecting essential data on digestion and absorption.FCT for their fellowships (SFRH/BPD/89992/2012 and SFRH/BPD/101181/2014). This study was supported by FCT under the scope of the Project PTDC/AGR-TEC/5215/2014, strategic funding of UID/BIO/04469/2013 unit; COMPETE 2020 (POCI-01-0145-FEDER-006684); BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020-Programa Operacional Regional do Norteinfo:eu-repo/semantics/publishedVersio

Diversity of non-clinical Acinetobacter species in a sub-saharan Africa region: evidence of carbapenem-hydrolysing class D-β-lactamase producers

[Excerpt] Although Acinetobacter baumannii has been the main agent for healthcare infections, recent reports suggest that some Acinetobacter environmental species should be considered as a potential cause of disease. In Angola, there are no previous data on its environmental reservoirs and resistance features. We aimed to unveil the occurrence and diversity of Acinetobacter species and the presence of resistance mechanisms in different non-clinical settings in Angola

Nanoemulsions for enhancement of curcumin bioavailability and their safety evaluation: effect of emulsifier type

This work aimed at evaluating the effects of different emulsifiers on curcumin-loaded nanoemulsions behavior during digestion, its safety and absorption, to develop nanoemulsions that provide safety and improved curcumin functionality. Nanoemulsions (NEs) were produced using two bio-based (lecithin (LEC) and rhamnolipids (RHAM)) and one synthetic (Tween®80 (TWE)) emulsifier at similar concentrations. Different NEs were subjected to in vitro digestion. The cytotoxicity and permeability tests were performed in Caco-2 cells. NE_TWE were stable during all phases of in vitro digestion, whereas NE_LEC and NE_RHAM were found to be unstable from the gastric phase. NE_TWE showed 100% of free fatty acids released, followed by NE_RHAM and NE_LEC. Curcumins bioaccessibility and stability increased in the following order: NE_LEC > NE_RHAM > NE_TWE. NE_LEC and NE_TWE did not show cytotoxic effects in any of the concentrations tested, while NE_RHAM presented high cytotoxicity in all concentrations tested. The apparent permeability coefficients were determined for NE_LEC and NE_TWE; however, the results were not statistically different. These results showed that the emulsifier used has a high impact on nanoemulsions behavior under the digestion process and on their cytotoxicity. This work contributed to the state-of-the-arts progress on the development of safer curcumin delivery systems with improved functionality, particularly regarding the proper selection of ingredients to produce said systems.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and under the scope of project PTDC/AGR-TEC/5215/2014.info:eu-repo/semantics/publishedVersio

Plant-based bigels for delivery of bioactive compounds: Influence of hydrogel:oleogel ratio and protein concentration on their physicochemical properties

Bigels are a class of soft matter systems with high potential in food industry as fortified ingredient replacers or food analogs. The aim of this work was to develop plant-based bigels using potato protein-based hydrogel and candelilla wax-based oleogel. The potato protein concentration and hydrogel:oleogel ratio effects on bigels production was assessed in terms of textural and rheological properties. The incorporation of curcumin and its bioaccessibility after in vitro digestion was also evaluated. All samples presented an oleogel-in-hydrogel structure arrangement. Increasing the protein concentration led to increased hardness and G*, improving the structure and consistency of bigels. The increase of oleogel fraction altered the distribution of oleogel droplets in the hydrogel matrix, affecting the hardness and the consistency of bigels. Overall, the increase of oleogel fraction and protein concentration allowed forming bigels with stronger mechanical properties and higher thermal resistance. The bigel showed a curcumin's bioaccessibility of 16.3 % and a curcumin's stability of 43.8 %, suggesting that this type of structures is promising for the delivery of bioactive compounds at the colon or for slow release of bioactive compounds. Overall, the results showed the possibility to develop potato protein-based bigels with interesting mechanical, rheological and thermal properties by changing the protein concentration and hydrogel:oleogel ratio, expanding the application of bigels in novel food products with high nutritional value and protein content, namely plant-based products.Raquel F. S. Gonçalves acknowledge the Foundation for Science and Technology (FCT) for her fellowship (SFRH/BD/140182/2018). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit, and by LABBELS – Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020

Nanoemulsion delivery systems: impact of emulsifier type on curcumins bioaccessibility during in vitro digestion

This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the Project PTDC/AGR-TEC/5215/2014, the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Nanostructures as conveyors of functionality in foods: the case of cannabidiol-based nanostructured lipid carriers

Nanostructures incorporating functional compounds have earned their place as a very efficient means of conveying functionality in foods. They may be used to tackle malnutrition, reduce calorie density, reduce food digestibility, increase micronutrient bioavailability, control gut health, allow personalized nutrition and provide appropriate food for the elderly, among other potential uses. Building such nanostructures, particularly when considering that they need to be edible, is a challenging task. This keynote will address the latest developments made by our research group towards tackling some of these challenges, together with our vision on what still needs to be done and which partnerships are important to lead us to further improve their performance. The incorporation of cannabidiol (CBD) into nanostructured lipid carriers (NLC) will be given as an example of a potential solution to mitigate its low bioavailability, which represents a big challenge for the development of CBD-products. Some details regarding their development (e.g., using innovative emulsifiers) will be provided and the consequences in the stability of CBD will be analysed.info:eu-repo/semantics/publishedVersio

Emulsions vs excipient emulsions as -tocopherol delivery systems: Formulation optimization and behaviour under in vitro digestion

Oil-in-water emulsions (EM) have been extensively used for the encapsulation of lipophilic bioactive compounds and posterior incorporation into food matrices to obtain functional foods. Conversely, novel excipient oil-in-water emulsions (EXC) present identical composition and structure as EM, albeit are not bioactive by themselves since no bioactive compound is encapsulated. Instead, EXC aims at improving the bioavailability of foods natural bioactive compounds upon co-ingestion with nutrient-rich foods. In this work, EM and EXC were produced and their stability and functionality as delivery systems for -tocopherol compared. Emulsions were formulated with corn oil and lecithin, and their composition was optimized using experimental designs. Formulations produced with 3 % lecithin and 5 % oil attained smallest particles sizes with the lowest polydispersity index of all tested formulations and remained stable up to 60 days. Encapsulation of -tocopherol did not have a significative impact on the structural properties of the particles produced with the same composition. -tocopherol stability during in vitro digestion was superior in EM regardless the processing methodology (EM stability < 50 %, EXC stability < 29 %), indicating that EM offered greater protection against the digestive environment. -tocopherols bioaccessibility was significantly increased when encapsulated or when digested with added excipient emulsions (8292 % and 8790 % for EM and EXC, respectively). In conclusion, EM were more efficient vehicles for the selected bioactive compound, however, the good results obtained with EXC imply that excipient emulsions have a great potential for applications on foods to improve their natural bioactive compounds bioavailability without the need of further processing.info:eu-repo/semantics/publishedVersio